pull PyCapsule_New() into the PYLOCK() section in poll_func()

If we call PyCapsule_New() from a thread created by libfuse before
ensuring the python interpreter is initialized, the thread state will be
NULL and the program will crash with SEGFAULT.

As suggested by David Lechner: pull the call to PyCapsule_New() into the
PYLOCK() section and open-code the rest of what was previously in the
PROLOGUE() macro.

Closes: #82

Author: brgl

fuseparts/_fusemodule.c

@@ -1272,15 +1272,31 @@ poll_func(const char *path, struct fuse_file_info *fi,
 	  struct fuse_pollhandle *ph, unsigned *reventsp)
 {
 	PyObject *pollhandle = Py_None;
+	int ret = -EINVAL;
+	PyObject *v;
+
+	PYLOCK();
 
 	if (ph)
 		pollhandle = PyCapsule_New(ph, pollhandle_name, pollhandle_destructor);
 
 #ifdef FIX_PATH_DECODING
-	PROLOGUE(PYO_CALLWITHFI(fi, poll_cb, O&O, &Path_AsDecodedUnicode, path, pollhandle));
+	v = PYO_CALLWITHFI(fi, poll_cb, O&O, &Path_AsDecodedUnicode, path, pollhandle);
 #else
-	PROLOGUE(PYO_CALLWITHFI(fi, poll_cb, sO, path, pollhandle));
+	v = PYO_CALLWITHFI(fi, poll_cb, sO, path, pollhandle);
 #endif
+	if (!v) {
+		PyErr_Print();
+		goto OUT;
+	}
+	if (v == Py_None) {
+		ret = 0;
+		goto OUT_DECREF;
+	}
+	if (PyInt_Check(v)) {
+		ret = PyInt_AsLong(v);
+		goto OUT_DECREF;
+	}
 
 OUT_DECREF:
 	Py_DECREF(v);